Question

why some people have become so insensitive towards other species

Answer 1

see let me give u a hindi phrase which will help u understand the ques clearly.the phrase is " jab taak jeb me paisa hai duniya puchegi bhai tu kaisa hai" . all these insensitive people just want to fill up their pockets. now a days due to ban on poaching the price of all the animal products except the daily use products is increased billion folds and to earn money they poach animals secretly.
this not actually insensitive it is being selfish actually. if it would have been plants instead of animals they would have "poached" plants also and the same for humans.
i hope this may help u.
 thank u.